Three Causes: Abundant moisture in lower
layers of atmosphere Mechanism to lift air,
allowing condensation Unstable air mass
Air Mass Thunderstorms Unequal heating within 1 air
mass Occur midday, last ~ ½
hour Frontal Thunderstorms
Caused by cold front
Lightning occurs when there is a charge separation in the cloud.
As a thunderstorm grows, electrical charges build up within the cloud, with positive charges at the top, and negative charges at the bottom.
Oppositely charged particles gather at the ground below the cloud.
A tornado is a violent, whirling column of air in contact with the ground.
Come from supercells – most intense thunderstorms
Most tornadoes form in the central and southern United States Continental polar air collides
with maritime tropical air from Gulf of Mexico
Hurricanes are large, rotating, low-pressure, storms Form from energy in warm,
tropical oceans Air rises due to existing
disturbance and low-pressure system is formed
What causes rotation? Coriolis effect
Hurricane Season is from June to November
